Rotary engine sealing means



Dec. 25, 1962' Filed June 8, 1960 G. E. MALLINCKRODT ROTARY ENGINESEALING MEANS 4A -Sheets-She t l Dec. 25, 1962 G. E. MALLINCKRODT3,070,074 ROTARY ENGINE SEALING MEANS Filed June 8, 1960 FIG. 3. 49

4 Sheets-Sheet 2 FIG. 2.

Dec 25, 1952 G. E. MALLIN K oDT 3,0709074 ROTARY ENGINE sE NG MEANSFiled June B, 1960 DEC- 25, 1952 G. E, MALLlNcKRoDT 3,070,074

ROTARY ENGINE SEALING MEANS Filed June 8, 1960 4 Sheets-Sheet 4 q i J MMM mw C JMU linited States arent @rfi-ice setenta Patented Elec. 25, lli

3,ll7l7f-i RTARY ENGlNE SELENG MEANS George E. Mallinclrrodt, Si. Ennis,Mo., assigner to Elliet Enterprises, incorporated, St. Louis, hito., acnrporation of Missouri Filed .lune 8, ldt), Ser. No. 34,7% 24 Claims.(ill. 121-49) This invention relates to rotary engine sealing means, andmore specifically to means for reducing gas leakage to or from rotaryengine combustion chambers and for reducing oil leakage past theirpiston seals. The general class ot' rotary engines to which theinvention relates and upon which it constitutes an improvement is shownfor example by my United States Patents 2,796,216 and 2,834,322. Theseshow so-called alternating-piston machines of this class.

Among the several objects of the invention may be noted the provision ofa rotary internal combustion engine of the alternating-piston type,having improved means adapted to prevent leakage of the working mediumto or from the combustion chambers through the `running rits betweentheir rotors and between such rotors and the stationary parts in whichsuch rotors operate; the provision of apparatus orr the class describedin which the rotor seals are particularly effective againsthigh-pressure losses during compression and expansion events; theprovision of rotor sealing means of the class described which wearevenly and slowly; and the provision of piston seals lor pistons ofrotary engins which will seal against leakage therethrough in eitherdirection relative to the oil supply system therefor. Gthcr objects andfeatures will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises tr e e ornents and combinations oielements, features of construction, and arrangements of parts which willbe exemplied in 'the structures hereinafter described, and the scope ofwhich will be indicated in the following claims.

In the accompanying drawings, in which one of various possibleembodiments of the invention is illustrated,

FlG. l is a fragmentary axial section through an alternating-pistonengine, illustrating the application thereto el one forni of rotorseeirrg means made 'according to the invention, bci taken on line l-llci 2 is an er arged fragmentary axial on line 2 2 of 3, showing detailsor a means between a rotor and adjacent stationary parts;

3 is a cross section, taken on line 3-5 of l FIG. 4 is an enlargedfragmentary detail view oi ce tain additional seal ig means betweenrotors;

HG. 5 is an exploded view, illustrating certain piston ring sealingelements;

FlG. 6 is a cross section, taken line 6*6 ot Fl FlG. 7 is a developedview, illustrating one of se sealing rings;

FlG. 8 is a fragmentary view similar to EEG. l, illustrating alternativeforni of rotor ealing means;

FIG. 9 is a fragmentary cross section taken on line @-9 of FlG. 8.

Corresponding reference characters indicate corre- G. verni spendingparts throughout the several views of the drawings.

The general type of rotary internal combustion engines of thealternstingpiston type to which this invention is directed appears saidPatents 2,796,216 and 2,834,322. rhus for a complete description of suchan engine, said patents be examined.

Referring now more particularly to El@ l, the adjacent ends of coaxialrotors of an alternating-piston engine are shown at numerals l and Theserotate in stationary, cheek-forming casing pieces and 7, respectively,which together with an outer ring 9 lform an annular cyl' er ofrectangular cross section. Adjacent the cylinder ll are annular pocketsZ and il. Each rotor l and carries a number of idertical pistons (tour,lor example), each Igroup of sur Q sions being connected to one rotorand extending over the other so as to interdigitate with the pistons onthe other rotor in the cylinder ll. Two typical pistons of this type onrotor 3 are indexed i3 in FlG. l, being located at l" intervals on thisrotor. These pistons are of thc oil-cooled and lubricated type set forthin said patents.

lt will be understood that there are two additional opposite pistons onrotor 3, located in a plane at right angles to the paper; also thatthere are four similar pistons on rotor but that `these do not show inliG. l because this rotor is shown in an angular relation with respectto rotor 3 and out of the plane of the paper. All of the pistons on bothrotors are of the same rectangular form, such as shown in FlG. l, eachrectangular form substantially matching that of the cross section of theannular cylinder ll formed by the cheeks of members 5" and 7, the insideof ring and the cylindrical forms between pistons i3 of rotors l andhere is a running clearance between each piston and the cylinder walls5, 7, 9 and the outsides of the mating rotor. rhis clearance requiressealing against gas and oil leakage as the pistons move relatively inthe cylinder ll in performing their onerations in the cycle of powerevents. rlire rotors tra s mit the movements imparted to them by thepistons to a power shaft shown at l5 by suitable drive means (not shown,being known in the art).

Rotor l is carried in a sleeve bearing l? located in frame piece E andin turn carries an internal slee e bearing 19 for the shaft le". Rotor 3is carried in a sleeve bearing 2l located in the frame piece i and alsocarries an internal sleeve bearing 253 for shaft Each bearing ffl' and2l is radially flanged, as shown at 29, to provide an inner face whichis approximately flush with a radial cheek of the cylinder lll.

Bearings i7 and 2l are prevented from rotating by dowels such as shownat 25', seated in the stationary mennber 5 and keyed into openings 27 inthe bearings. The don/els 25' for holding the bearing are shown, butthose for holding bearing 2l do not appear because they are outside theplane of the paper in PEG. l. The flanges are located in pockets 2 andffl, respectively. The outside radial walls of the rotors l and 3 turnagainst the inner faces of llanges 2, at which areas leakage may occurfrom the suction, com sression, combustion, and exhaust events occurringin the spaces between the pistons. lt is to prevent this that annularside sealing assemblies shown in NGS. 1, 2, 3 and 6 are employed forsealing the rotors relative to the side pieces and 7. Since each annularseal is a duplicate of the other, a description or" one will suilce forboth, like numerals being employed for each.

Referring to the left-hand annular seal (FIGS. l, 2, 3 and 6), numeral3l indicates a radial ball race for roller or ball bearings 33. Thisrace 3l surrounds the adiacent bearing flange. 29. The latter, as bestshown in FlG. 3, is marginally provided with a range R of pockets S5 inwhich biasing compression springs 317 are seated. The range R of pockets3S and contained springs 37 is adjacent to the range of movements of thepistons i3 within which gaseous compression and explosive eXpansionevents occur between the pistons l, since any leakage during such eventsis the most critical to efficient 0peration.

'lhe ball bearings 33 are surrounded by a radially tensioned,expansively springy annular race il which is split at one point, .suchas shown at i3 in FlG. 3, to permit it to exert expansive force. Therace il is L-shaped in cross section, having an inside smoothcylindrical surface l5 which radially supports the balls 33, and a atradial surface i7 which supports ball bearings 49. The balls 49 arecarried in an axial race 5i, slidably located in an axially disposedgroove 53 locate-d in the stationary member (or 7, as the case may be).The race 5l contains axially directed pockets 55 for the reception ofaxially locating biasing compression springs 57. The springs 57 reactupon the stationary bottom of groove 53 to force the race 5l to pressthe balls di) axially against the race di.

Located in the angular seat of the L.shaped race 41 are a plurality(live in the present case) of circular ringforming laminated springsealing rings 59. A developed view of a typical one of the spring rings59 is shown in FIG. 7. Each is oppositely notched at its opposite ends,as shown at 6i and 63, to form an interdigitated overlap when itsopposite ends are brought together by looping it into circular form. itwill be understood that since each ring 59 in the plurality is to benested with others in the angular seat of the race 4l and each ring mustbe of different diameter, the developed length of each will be slightlydifferent. Thus the developed length of each ring 59 that lies outsideof another is slightly longer than the latter. It is also preferablethatL each alternate ring have opposite notchings 6l and 63 at itsopposite ends reversed in aspect for maximum sealing eifect when insealing position, although this is not absolutely necessary.

As shown in FIG. 6, the locations of the springs 57 are distributedaround the periphery of the race 51, with a group of them being bunchedclosely in the range R1. The range R of the springs 37 shown in FIG. 3,and the range R1 of the springs d'7 shown in FIG. 6, appear on oppositesides of these figures but they are actually adjacent one another, thecross sections of FlGS. 3 and 6 being viewed in opposite directions inFiG. 1. Thus the angular range R (FIG. 3) of the springs 37, and theangular range R1 (FlG. 6) of the closely spaced groups of springs 57,lie contiguously. The result is that the ribbonlike spring rings 59 havetheir Hat sides more forcefully pushed radially against the stationarymember 5 (0r 7, as the case may be) in the range R than elsewhere. Also,the spring rings 5S" have their marginal edges more forcefully pushedagainst their contiguous rotor l (or 3, as the case may be) in the rangeR1 than elsewhere. An important feature also is that the axial loadingof the assembly of rings S by the axial springs 57 is so related to theradial loading of assembly 5S by the radial springs 37,

that the predominant frictional drag effect is between the assembly 4iand its adjacent variable-velocity rotor l (or 3, as the case may be).rl`he advantage of this arrangement is as follows:

As the rotors 1l and 3 alternate their rotations under successive eventsbetween their pistons 13 in the range R or R1, there will be asubstantial radial sealing effect of the rings 59 on the member 5 (or 7,as the case may be) in the range R, and there will be a substantialaxial sealing effect of these rings on the rotor il (or 3, as the casemay be) in the contiguous range R1. Not only does this have theadvantage of providing a very effective seal against leakage from thecritical compression and expansion events between the pistons R3, but ithas the added advantage that the edges of the groups of rings 5t? areurged into predominantly strong frictional engagements with theirrespective rotors so that these rings tend to be dragged with theirrespectively adjacent rotors. Thus as each rotor rotates underconditions of low acceleration, the adjacent ring S9 tends to rotatewith it, along with the adjacent race dit. At this ttirne the outermostring 59 will rub on 5 or 7, as the case may be. On the other hand, whena rotor attains substantial acceleration or deceleration, as at the endof a compression event and the start of an expansion event, the inertiaof the assembly of adjacent race il and rings 59 will result in slip ofsuch rings with respect to the rotor. Some relative slippage will alsooccur intermittently between the rings 59 themselves. This in generalhas the effect of constantly bringing new contact surfaces intosubstantial pressure engagement between the rings, rotors and framepieces, with the result that even wear and long effective sealing lifeaccrue. in short, the assemblies of rings 5S intermittently creep aroundthe pockets 2 and 4 as they become frictionally connect-ed to anddisconnected from the rotors as the latter vary their angular'velocities in performing their cyclic power functions. The inner surfaceof each race il is cylindrical, so that it may move freely in an axialdirection with respect to the balls 33. Also, the radial face of eachrace di is dat, so that it may move eccentrically `ander eccentricpressure of the rang-e R of springs 37.

Sealing means are also required at the axial abutnients between therotors l and 3. Such sealing means are shown enlarged in -FlGn 4. Onecomponent of these means is constituted by two adjacent flat rings 65and 67 which are located between the rotors l and E5 and which locatedbetween the rotors i and 3 and which abut one another. These are weldedas shown at 69 along their inside interfacial regions, being leftunwelded at their ontside interfacial regions, as shown at 7 i. rIheirmargins in region 7l are adiacently beveled as shown at 63. Inside therings 65 and o7 is located an outwardly springy split sleeve '73. Thesplit is shown at 75 in FIG. l. This sleeve is held in place by rings 77and 79, which have press fits in hollow ends of the rotors l and 3. Therings "77 and 79 not only hold the sleeve 73 in position, but formannular oil passages. Any leakage that tends to occur from the spacesoutside of the rotors 1 and 3 from between the pistons 13 thereon isblocked by the rings 65, 67 and sleeve 73. rl`he fact that the weldedrings 65 and 67 are unwelded between them at their outer peripheriesenhances their sealing effects, since under leakage pressure they tendto spread apart axially against the rotors, particularly if they areadjacently beveled as at dit.

Each piston 13 is of the general oil-cooled and lubricated type shown inthe abovementioned patents, having similar angular piston sealing partsin ring slots 6 which form sealing rings pressed outward by means ofsprings such as 251. The ring-sealing parts have been improved herein,as illustrated in FIG. 5. They are flat and adapted to be paired inpiston slots such as indicated at 6. Each cordinated pair ofring-sealing parts is constituted by two flat angle members 83 and 35which are identical, as shown. The angle members have openings 37 attheir corners for the loose reception and retention of discs 89 whichhave thicknesses the same as those of the members S3 and 85. Theopenings $7 are connected to the interior corners of the ring-formingmembers by slots 3S. The holes 37, in View of the slots 8S and somewhatloose tits of the discs 89 therein, provide for springiness between theright-angled legs il and 93. The discs S9 prevent leakage through theholes 87 when the discs are located in the holes, as shown in FlG. l.

Each leg 91 is beveled as shown at 95, and each leg 93 is provided witha cooperating right-angular notch, as shown at 97. The notches 97 andbevels 95 are adapted to be brought in cooperative relation as shown inFIG. l, leaving oppositely converging or triangular openings 99therebetween. For sealing purposes, srnall freely movable or floatingdiscs itil are located in said triangular openings 99. Location isaccomplished, as shown in PEG. 5, i.e., by manufacturing each ringmember, which is hardened, with a small disc litlfw attached by a verythin breakable neck M35 to the respective bevel 9S and of equalthickness thereto. This arrangement is illustrated in connection withthe angle member 85, as shown in FIG. 5. Each disc w3 thus becomesautomatically placed in a triangular opening 99 when the angle membersare cooperatively assembled in the ring slot 6 of a piston li. Then whenthe engine is started, vibration breaks away each disc M93, as suggestedin connection with the in the pistons 13' member 83 shown in FlG. 5. Theresult is as shown in FIG. 1, wherein each triangular opening 99contains a free-oating disc 101 which will seal the abutment between thelegs 91 and 93 of the members 83 and 5, regardless of the direction inwhich leakage tends to occur through the openings 99. Under eitherinwardly or outwardly directed gaseous pressure, the discs :3 will takeup wedging positions in the corners of the triangular spaces 99, whichwill seal against either inward or outside outward leakage.

Piston oil-cooling and lubricating means are described in said patents.As applied in the present construction, lubrication occurs as follows:

Oil inlet ports are located at 167. These have branches 109 leading intothe space between rotors. As shown in the case of rotor 3 in FIG. 1, oilmay escape through ring 79, passage 111, via port 116 and into thecenter circulating passages 114 of the upper piston 13. This is forcooling purposes as set forth in said patents. A return passage is shownin connection with the other lower piston 13 shown in FlG. 1, whereinnumeral 117 is the outlet from the center cooling passage 114. Thiscommunicates through passages 119 with the spaces around the adjacentsealing assembly shown at the right and thence through ports 121 andoutlet passage 123. The passages 123 and 107 are connected by a suitablepressurized circulating system, not shown.

Some of the oil from between rotors 1 and 3 escapes through passage 113and enters each piston through a port 11S for lubricating the anglesealing members 83 and 8S. Very little of the oil delivered through theport 11S for lubricating the angle members is lost through the sealingrings 59, but whatever amount of it may be lost will return throughports 121 to the outlet passages 123.

It will be noted, as regards the description of the oil circuits, thatfor clarity, inlets such as 111, 113 for the p 'sto-ns are shown only inconnection with the upper piston 13 in FEU. 1, and that the outlets suchas 119 are shown only in connection with the lower piston 13 thereshown. This is to avoid confusion in illustration, but it will beunderstood that each piston on each rotor contains a full complement ofpassages such as 111, 113 and 119. It will also be understood that thepassages are formed through the material composing the connectionsbetween the respective pistons and the central portions of the rotors onwhich they are mounted. ln PEG. l no passages are shown for pistons onthe rotor 1 because its pistons are out of the plane of the section.Further details regarding the oil circulation will not be required, inview of the disclosure of similar oil-circulating means described insaid paents.

FIGS. 8 and 9 illustrate another form of the rotor sealing means whichis alternative to that shown in FIGS. 1 3. In order to avoid repetitionsdescrption, parts in FIGS. 8 and 9 that correspond in function to thoseshown in FIGS. 1-3 have the same numbers except that the ninnbers areprimed, since the detailed shapes of some of such corresponding partsare slightly diiferent in FIGS. 8 and 9. Description of the primenumbered parts will not be repeated. Points of dierence will be found inthe following description, wherein additionai numerals are used forparts not shown or described in connection with FIGS. 1-3.

Referring to FGS. 8 and 9, the flanges 29 of t. e bearings 17 and 21'are modied so as to be keyed in position by means of hollow thimhles125. These thimbles connect with passages 127 in casing parts S and 7.They also connect with peripheral grooves 129 in the anges with outlets131 (see openings 12o). The rotors 1 and 3 contain passages 133, whichconnect with the grooves 129 and also with transverse slots 135 in therespective rotors. The slots 125 are at the bases of the spaces 123which contain the pston sealing parts. The flanges 29 are marginallymodified to form recesses 13-7 for axial spring 139, adapted to pressrings 141 against the rotors 1 and 3', respectively. The rings 141 *dare of the split lapped-end type, indicated at 142 in FIG. 9.

In the pockets 2', 4 are located ribbon-like sealing rings 143 whichhave axial lands 145 seating axially on the margins of the rotors. Theserings are of the split end lapped type, tending to spring outward intospringing engagement with the stationary members 5' and 7',respectively. These tend to form radial seals with the sationary paris Sand 7. The split lapped-end arrangement is illustrated at 14d in PEG. 9.Passages 147 convey foil under pressure to the pockets 2, 4', thustending to press the lands ldd, sealing rings 1.013 against therespective rotors 1 and 3. Thus radial and axial seals obtained'corresponding to those provided by the ribbons 59 in EEG. 1. Anyleakage of oil past the sealing rings 143 moves through pressure reliefpassages 135, 133, 129, thimbles 12S and passages 127 to outlet passages131. Any leakage that passes the rings 141 also finds its way betweenthe parts 29 and the respective rotors 1 and 3 to the sssages 131 viapassages 129, 1.16, thimbles 12S and passages 127.

1n View of the lands 145, unbalanced pressure is applied to the rings143 by the oil pressure varriving through passages 1d?. This pressure isadjusted so as to force the rings toward the respective rotors 1 and 3,causing them to tend to move with the rotors during periods ofcomparatively low rotor acceleration or deceleration but allowing theserings 143 to slip with respect to the rotors under conditions ofcomparatively higher accelerations and decelerations. Thus it will beseen that as the engine operates the rings 143 will alternately cling toand release from the respective rotors. Thus the rings 143intermittently creep from one position to another relative to the rotorsand parts 5 and 7', with resulting minimization and equalization ofwear. The optimum condition of intermittent creep of the rings 143 maybe obtained by adjusting the pressure in the inlets 147.

Advantage of various features of the invention are as follows:

(l) The rotor sealing rings 59 are strongly pressed into sealingengagements with 4the respective rotors 1 and 3 over the range R1 shownin FIG. 6, which has a two-fold result:

(a) Adequate sealing is obtained in the range of compression andexpansion or tiring events bctween pistons, under which conditions mostleakage ordinarily occurs; and,

he comparatively high Contact pressure, with pressures against therespective rotors, causes the above-mentioned tendency of the ring seals59 to rotate with the rotors throughout temporary intervals of lowacceleration or deceleration, but to slide with respect to themthroughout intervals of higher acceleration or deceleration, therebycausing evenly distributed Wear and consequent long life. Thus each ringseal 59 intermittently rota-tes or creeps with respect to the stationaryparts o" and 7.

(2) The localized radial spring over range R, as shown in FIG. 3,enhances the radial seal against stationary portions of the engine inIthe above-mentioned range R of compression and expansion events.

(3) The inwardly partially welded adjacent rings 65, 67, and the innerspring sleeve 73, effectively prevent leakage from the space betweenpistons into the space between rotors. This is because of the spreadingaction which may occur between the free outer parts 71 of the rings ando7.

ressure on race 41 (4) The improved abutments between legs 91 and 93 ofthe angular sealing ring members 83 and 35 with the associated lloatingdiscs 1113, reduce oil and gas leakage at said abutments, whether or notthe leakage tends to occur inwardly, as in the case of suction eventsbetween sprao'z's Z pistons, or outwardly, under compression, expansionor exhaust events.

The self-releasing discs M3 provide for their convenient insertion whenthe sealing components 83 and 85 are placed in the pistons i3.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions wi-thoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim:

l. Sealing means for use between a rotor and casing of a rotaryalternating-piston machine, comprising circular and radially springingring-sealing means radially springingly engaging the casing and axiallyengaging the rotor, said ring-sealing means compri-sing an assembly ofaxially laminated circular metal ribbons biased edgewise and axiallyagainst the side of the rotor and Ibia-sed radially atwise against thewall of the cylindical pocket in the casing, both engagements being withcircular sliding contacts, and means adapted to bias the ring-sealingmeans into rotor engagement with a pressure sucient that the ring willmove with the rotor under condi- -tions of comparatively low rotoracceleration or deceleration but will slip with respect to the rotorunder conditions of comparatively high rotor acceleration or deceleration.

2. Sealing means according to claim l, wherein sai.l ring-sealing meansincludes axially and radially disposed roller-engaging surfaces, rollermeans engaging said surfaces, and axially and radially operative rollerforcing means.

3. Sealing means according to claim 2, wherein said axially and radiallyoperative roller forcing means are axially and radially movable rollerraces backed axially and radially by arrays of expansive springs.

4. Sealing means according to claim 3, wherein each array of springs isconcentrated throughout a limited circular range of the same.

5. Sealing means for use between the rotors and casing of a rotaryalternating-piston machine wherein the rotors accelerate and decelerateangularly, comprising ring seals adapted respectively rotatably toengage a rotor and the casing with circular sliding contacts, each ringseal comprising an assembly of axially laminated circular metal ribbonsbiased edgewise and axially against the side of the rotor, `and biasedatwise against the wall of the cylindrical pocket in the casing, andmeans adapted to bias each ring seal into rotor engagement with agreater frictional circular drag therebetween than its frictionalcirculaldrag in its engagement with the casing, said greater frictionalcircular drag being suiiicient to carry each ring seal with a rotor atrotor speeds during periods of relatively low rotor acceleration andinertially to release the ring seal from a rotor during periods ofrelatively high acceleration and deceleration of the latter.

6. Sealing means according to claim 5, including an annular first racesupporting each ring seal, said race having inside cylindrical andendwise flat forms, second inner and third endwise movable ball racescarrying balls engaging said forms respectively and inner radial :andendwise axial biasing means positioned to bias said ysecond inner andthird endwise races toward the first race.

7. Sealing means according to claim 6, wherein said 'biasing means areconstituted by localized arrays of :springs operative on said second andthird races.

8. Sealing means for use between a rotor and casing Aof a rotaryalternating-piston machine, comprising a ring seal composed of alaminated assembly of circular metal ribbons located in a cylindricalpocket of the casing and arranged for sliding Contact therewith and witha side of the rotor, a iirst race supporting said assembly and having ailat side and a cylindrical interior, a second ball race carrying ballsbiased thereby into engagement with said cylindrical interior of saidrst race, a third axially movable ball race carrying balls engageablewith said dat side of the first race, and an array of radially disposedsprings engaging said third ball race adapted to force the balls thereofinto axial engagement with said first race.

9. Sealing means according to claim S, wherein said iirst race is splitand outwardly sprung within said assembly.

10. Sealing means for use between a rotor and casing of a rotaryalternating-piston machine, comprising a ring seal composed of alaminated assembly of circular metal ribbons each having abutted endsand located in a cylindrical pocket of the casing and arranged forfacewise sliding Contact therewith and located adjacent a side of therotor for edgewise sliding Contact therewith, a rst split `and outwardlysprung race of L-shaped cross section supporting said assembly andhaving a flat side and a cylindrical interior, an eccentrically movablesecond ball race carrying balls engaging within said cylindricalinterior, an array of radially disposed springs within said second ballrace adapted to force said second ball race radially against said firstL-shaped race with an eccentric application of force, a third axialmovable ball race carrying balls engageable with said lat side of thefirst race, and an array of radially disposed springs engaging saidthird ball race adapted to force said third ball race radially with saidfirst race with an eccentric application of force.

1l. Sealing means according to claim 10, wherein the ranges of saideccentric applications of forces are substantially coextensive.

12. Sealing means for use between abutting rotors of alternating-pistonengines comprising adiacent rings between said rotors and respectivelyengaging them fiatwise, the inside margins of said rings being joinedand their outside margins being free.

13. Sealing means according to claim 12, including a cylindrical springring located within the joined margins `of said adjacent rings.

14. Sealing means for use between abutting rotors of alternating-pistonengines, comprising interfacially engage flat rings between said rotorsrespectively engaging them iiatwise, the interfacial engagements betweensaid rings being circularly connected throughout an interior area andunconnected throughout an exterior area.

l5. Sealing means according to claim 14, wherein adjacent margins ofsaid unconnected area are beveled.

16. Sealing means for use between a rotor and a recessed casing of arotary alternating-piston machine, comprising a ring seal composed of asplit spring ring radially sprung into engagement with the recess in thecasing, said ring having lands axially engaging the rotor, means forintroducing iluid under pressure into said recess to force the ringagainst the rotor, and iluid relief passages in the rotor and the casingconnecting with the space between said lands.

17. Sealing means according to claim 16, wherein said relief passagesinclude a circular passage in the casing with which the portion of therelief passage in the rotor continuously connects.

18. Sealing means according to claim 16, including an additional ringseal between the casing and the rotor adapted to resist leakage underpressure that might occur between the casing and the rotor to saidrelief passages.

19. Ring-sealing means for rectangular pistons comprising flatcooperatively arranged L-shaped members, each member having two joinedside legs having free ends abutting the free ends of the legs of theother L- shaped member respectively substantially to form a rectangle ofthe cooperatively :arranged L-shaped members, the abutting ends of thelegs being shaped to form wedgeshaped enclosing pockets, and a movableilat sealing member trapped in each pocket for movement into wedgingengagement therein with the adjacent leg ends.

20. Ring-sealing means according to claim 19, wherein each pocket is inthe general form of a triangle and said sealing member is or" circulardisc form.

21. Ring-sealing means according to claim 20, wherein prior to assemblyin a piston each disc has a temporary connection with one free endportion of one leg of one L-shaped member so as to be positioned in apocket upon assembly and to break free upon operation of the piston foroating movements in the respective pocket.

22. Sealing means for use between a rotor and casing of a rotaryalternating-piston machine, comprising circular and radially springingring-sealing means radially springingly engaging the casing and axiallyengaging the l@ rotor, both engagements being with circular slidingcontacts, said ring-sealing means having axially and radially disposedroller-engaging surfaces, roller means engaging said surfaces, andaxially and radially operative roller forcing means.

23. Sealing means according to claim 22, wherein said axially andradially operative roller forcing means are axially and radially movableroller races backed axially and radially by arrays of expansive springs.

24. Sealing means according to claim 23, wherein a number of springs ineach array is concentrated throughout a limited circular range whichsubtends less than 360 degrees of arc.

References Cited in the iile of this patent UNITED STATES PATENTS1,994,858 Lack et al. Mar. 19, 1935 2,834,322 Mallinckrodt May 13, 1958FOREIGN PATENTS 197,01() Great Britain May 3, 1923 UNITED STATES PATENToEEIcE CERTIFICATE 0E CORRECTION Patent No., 39O7OO74 December 25v 1962George E.g Mallinckrodt It is hereby certified that error appears in theabove numbered patent requiring correction and that the said LettersPatent should read as corrected below.

In the gnant1 lines 2 and 3v totB u'Elliot Enterprises,z

IncorqooratedY o Sto Louisl Missourin read Elliot EntenprisesIncorporatedY of St Louis CountyE Missouri in the heading to the printedspecification9 lines 3 and 4v for "Elliot Entenprises Incorporated St.,L0uis Moo" read Elliot Enterpyfises,I Incorporated, Stia Louis CountyvMoo en; column 3v line 70, for "ttime'" need m time column lv line 2lgstrike out "which are located between the rotors l and 3 and e=-; columnq line 121 strike out the commeD Signed and sealed this 9th day of July1963o (SEAL) Attest:

DAVID L.. LADD ERNEST W. SWIDEB Commissioner of Patents AttestingOfficer

